Question: what are the metabolite starts with v
Paraphrase: Name the metabolite starts with the letter v.
SPARQL (Wikidata): SELECT DISTINCT ?sbj ?sbj_label WHERE { ?sbj wdt:P31 wd:Q407595 . ?sbj rdfs:label ?sbj_label . FILTER(STRSTARTS(lcase(?sbj_label), 'v')) . FILTER (lang(?sbj_label) = 'en') } LIMIT 25 
Answer: violaxanthin, violaxanthin